Orthodontic skeletal anchorage device

ABSTRACT

The invention proposes an orthodontic anchorage device, which may be used in combination with others, comprising a plate with two, three or four pointed end stems distributed on one of its surfaces and at least two holes at the ends adapted for the insertion of micro screws. These stems are intended to slightly rest on the bone through the palatine mucosa, preventing the entire appliance from digging into the palate.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.16/838,643, filed Apr. 2, 2020, the entirety of which is incorporatedherein by reference.

FIELD OF THE ART

The invention belongs to the field of orthodontics, in particular, tobone anchorage devices for the manufacture of various appliances. Theanchorage device of the invention can also be used alone or as part of acomplex system in which each element is a device according to theinvention in its various implementations.

BACKGROUND OF THE INVENTION

In orthodontic treatments, the use of skeletal anchors (fixed andimmovable point in the bone from which all types of orthodontic movementof the teeth or neighboring bone structures can be made) has becomepopular. Through this type of support or anchorage, dental movementsthat were unthinkable a few years ago can be carried out. The skeletalanchorage devices that are usually used with micro screws are miniplatesor plates. They can have two types of support: dental support (1) ormicro screws with a support plate or base (2).

1. It is known that skeletal anchorage orthodontic appliances used inconjunction with micro screws need to be supported on the adjacent teethto avoid their displacement towards the palate and the consequent injuryto it by the force exerted when the screws are threaded in the directionof the palate. This appliance is kept fixed and in a stable position atthe site of the operation, thanks to two opposing forces: the microscrews that exert pressure towards the palate and the dental supportthat neutralizes this force and keeps the device in a position that is afew millimeters away from the palate and stabilized.

2. An alternative to the use of dental supports is the previousplacement of micro screws in the palate with a support base on which theplate is supported. Once this first operation has been carried out, animpression or measurement is taken with dental silicone using theappropriate technique in order to reposition them on a plaster model ofthe mouth. On this replica of the mouth the preparation of the applianceis carried out in the laboratory. Once the anchorage device has beenmade, it is taken to the mouth and then fixed by means of some coverscrews or caps that are screwed onto the micro screws initially placed.With this technique, the device is held between the support base of theprimary micro screw and the second cover screw placed over the firstone, but this appliance is cumbersome and requires several previoussteps to place the device in the mouth, each step being a source oferror. Therefore, the appliance based on this technique involvesnumerous repetitions, due to imprecise adjustments, despite the factthat this technique is carried out meticulously.

Once the auxiliary skeletal anchorage appliance is in place, toothmovements can be made supported by the appliance in the three planes ofspace: in the transverse or lateral plane (expansion and compression),in the vertical plane up and down (intrusion and extrusion) and in thesagittal plane forward or backward (protrusion and retrusion of thejawbone), as well as the correction of dental arch asymmetries and thebasic movements of the teeth described as 1st, 2nd and 3rd order (CanutBrusola José A. Clinical Orthodontics, Second Edition Barcelona: MassonPublishing House. 1999 William R. Proffit (1994); Ortodoncia. Teoría yPráctica. Bases biológicas del tratamiento ortodóntico. Second Edition.Mosby, Madrid).

SUMMARY OF THE INVENTION

The object of the present invention is to provide a simpler orthodonticskeletal anchorage device that avoids the need of dental supports toprevent the above-mentioned appliance from digging into the palatinemucosa.

Similarly, the proposed system avoids the prior placement of microscrews, the use of replicas for making appliances and the use of coverscrews described above.

To this end, the invention proposes an orthodontic anchorage device(which may be used in combination with others) comprising a plate withtwo, three or four pointed end support stems distributed on one of itssurfaces and at least two holes at the ends adapted for the insertion ofmicro screws. These support stems (these and only these) rest slightlyon the bone, crossing the palatine mucosa and preventing the entireappliance from digging into the palate.

In this way, the prepared appliance is kept correctly positioned andstabilized by two antagonistic forces, the pressure of the micro screwsthat fix it and the support of the pointed stems resting on the jawbone.

BRIEF DESCRIPTION OF THE FIGURES

In order to assist in a better understanding of the features of theinvention and to complement this description, the following figures,which are illustrative and not restrictive in nature, are attached as anintegral part thereof:

FIG. 1 a and 1 b show a lateral device and its placement according tothe invention;

FIG. 2 is a medial device according to the invention;

FIG. 3 shows an expansion screw, consisting of two modified side devicesjoined by a threaded rod; and

FIG. 4 shows one of the devices already placed on the palatine mucosaand fitted with wires to promote orthodontic movements.

DETAILED DESCRIPTION

With reference to FIG. 1 a , the present invention solves the technicalproblem of anchorage support by means of an anchorage device providedwith at least an elongated shaped plate 1 with rounded corners. On oneof its faces, preferably in the central area, the plate is provided withtwo (2), three (3) or four (4) bone support stems ending in a point 2.In addition, the device is fitted with at least two holes 3 adapted forthe insertion of micro screws, at the ends of the plate, along itslongitudinal axis.

The invention provides a simple solution, which is not included in anyof the devices used in orthodontic treatments, consisting of the factthat the bone support stems compensate and prevent that, due to thepressure made when inserting the micro screws for the placement of theappliance, the latter is driven into the palatine mucosa, making thepalatine's functionality unfeasible.

The stems 2, pins or cylindrical abutments with conical tips serve asstabilizers for the appliance and at they provide secondary anchorage orbone support for the primary anchorage micro screws of the appliance.

The stems 2 can be fixed and constitute a single unit with the centralbodies or can be removed by means of a thread to be able to change themin order to have the necessary length to adapt the appliance to eachcase, according to the maxillary morphology. In another embodiment, thestems 2 can be complemented with extensions that allow for varying thelength of the stems to keep the appliance at the right distance from thepalate.

FIG. 1 a shows an implementation of the invention in the form of a sideplate, which has a plate 1 having a rectangular shape with roundedcorners and edges. FIG. 1 a shows one of the long sides 4 slightlycurved (i.e. one side has a concavity, with the center of curvatureoutside the plate), but the plate can be rectangular, with roundedcorners and parallel sides. The ends have two holes 3 for insertingmicro screws, with their centers on the longitudinal axis of the device.The device can be used indistinctly on the right or left side of thepalate, as appropriate, or even longitudinally to replace the centralplate described below, in the case of very narrow palates. The device isfixed to the maxillary bone by means of two micro screws that penetratethe bone through the two holes located in the longitudinal axis. Thestems 2 are distributed on the plate, preferably in the central area,ending in a point, forming the skeletal support, an essential part ofthe invention.

The lateral plate is designed to be used in pairs and as a base on whicha rapid expansion screw, already known in the previous state of the art,is welded to make a purely skeletal anchorage or a hybrid anchoragepalatal expander if the arms of the expansion screws are fixed to themolar bands, constituting a hybrid expander (dental and skeletalsupport). It can also be placed transversely as a single piece and theappropriate wires or springs can be welded to it to promote anyorthodontic movement (FIG. 4 ). On the opposite side of the stems, thereare optionally two half-round slits 7 and a trapezoidal projection 8between the two notches. Wires can be placed over the slits 7 and incontact with this projection (FIG. 4 ) to facilitate dental movements.

With reference to FIG. 2 , a medial plate (placed in the center of thepalate) in accordance with the invention has a Y-shaped structure, withboth long edges 4 curved towards the transversal axis of the plate 1.The mesial end (anterior), ends in three semicircular lobes 5 over whicha wire is welded, which, when properly shaped, allows the performance ofnumerous dental movements. The lobes on the sides are provided withholes 3 for the placement of the micro screws that hold the plate to themaxillary bone. The distal end is provided with a third hole 3 toaccommodate a third micro screw. Three support stems 2 are placed as inthe previous implementation in the center of the plate 1 and by restingthem slightly on the bone they provide the stability of the device and aproper skeletal anchorage. A steel wire can be welded onto the lobeswhich, once shaped and properly connected to the upper molars, allowsvarious movements to be made on them by means of auxiliary attachmentssuch as springs, pins and set screws of different structures.

This plate is used indifferently with the one previously mentioned as aside plate being absolutely interchangeable having as a significantdifference the insertion with three micro screws instead of two,maintaining the same functions as the side plate.

FIG. 3 shows a skeletal expansion screw according to the invention. Thisscrew comprises two symmetrical plates 1 which, like the whole system,has bone support stems in common and can be attached to the plates orthreaded into them and therefore they are removable. The lateral bodiesmay be provided with slits 7 and trapezoidal projections 8 as in thefirst implementation, intended for welding a round wire, the purpose ofwhich is to attach it at its terminal end to the bands of the maxillarymolars or to any spring intended to provide anchorage for orthodonticmovements.

The central bodies have two stems 3 each on their central axis at thejunction between the front and middle third portion, and the middle andback third portion. The stems 2 are intended to provide support on themaxillary bone, separating the bone from the expansion screw, and inturn serving as a secondary bone anchorage. Finally, the lateral bodieshave three lateral holes. The end holes are designed to accommodate twoconnecting rods 9 at the anterior and posterior ends. These serve toconnect the bodies and allow them to move horizontally along the entirelength of the rods.

The central hole, slightly larger in diameter than the previous ones,has an internal thread and houses a threaded rod in the center of whicha hexagonal nut 10 with holes on each side is placed to facilitate theactivation of the rod, according to which the bodies are separated. Thisrod threaded into the plates is characterized by a reverse thread, thismeans that the right side of the threaded rod from the hexagonal nutplaced in the center of the same has a right-hand rotation thread andthe other part of the rod has a left-hand thread so that when it isrotated (activated), if the direction of rotation is clockwise, theplates are separated and, if it is counterclockwise, they areapproached.

Finally, it should be added that the whole system is used by assemblingor combining some pieces with others by means of welding them, thusallowing the creation of a highly versatile appliance with only threeelements (a central plate, a lateral plate and an expansion screw) tocarry out most orthodontic movements.

In view of this description and figures, the person skilled in the artmay understand that the invention has been described according to somepreferential embodiments thereof, but that multiple variations may beintroduced in said preferential embodiments, without exceeding theobject of the invention as claimed.

What is claimed is:
 1. An orthodontic anchorage device comprising: atleast one elongated plate with rounded corners, wherein the elongatedplate comprises: at least two holes at ends of the elongated plate, theat least two holes adapted for the insertion of bone anchorage microscrews; and between two to four point-ended bone support stemsdistributed on one side of the elongated plate.
 2. The device of claim1, wherein the stems are removable by means of a thread.
 3. The deviceof claim 1, wherein the elongate plate has a rectangular shape with onelong side curved towards the center of the plate.
 4. The device of claim2, wherein the elongate plate has a rectangular shape with one long sidecurved towards the center of the plate.
 5. The device of claim 1,wherein: the elongate plate is Y-shaped; the elongate plate includesthree lobes at a first end of the elongate plate; a first lobe and asecond lobe of the three lobes, wherein each of the first lobe and thesecond lobe define a hole adapted to introduce bone anchorage microscrews; and the elongate plate defines a third hole at a second end ofthe elongate plate adapted to intro a bone anchorage micro screw.
 6. Thedevice of claim 2, wherein: the elongate plate is Y-shaped; the elongateplate includes three lobes at a first end of the elongate plate; a firstlobe and a second lobe of the three lobes, wherein each of the firstlobe and the second lobe define a hole adapted to introduce boneanchorage micro screws; and the elongate plate defines a third hole at asecond end of the elongate plate adapted to intro a bone anchorage microscrew.
 7. The device of 1, wherein the elongated plate is a firstelongated plate and the device further comprises: a second elongateplate; wherein the first elongate plate and the second elongate plateeach have: two point-ended bone support stems; and at least one hole atan end of each of the first elongate plate and the second elongateplate; and wherein the first elongate plate and the second elongate arejoined by two connecting rods, a central threaded rod, and a hexagonalnut, the central threaded rod and the hexagonal nut interact to bringthe first elongate plate and the second elongate plate closer togetherand further apart.
 8. The device of 2, wherein the elongated plate is afirst elongated plate and the device further comprises: a secondelongate plate; wherein the first elongate plate and the second elongateplate each have: two point-ended bone support stems; and at least onehole at an end of the first elongate plate and the second elongateplate; and wherein the first elongate plate and the second elongate arejoined by two connecting rods, a central threaded rod, and a hexagonalnut, the central threaded rod and the hexagonal nut interact to bringthe first elongate plate and the second elongate plate closer togetherand further apart.
 9. The device of claim 1, wherein the elongate platehas a trapezoidal projection in a middle portion of the elongate plate,a first half-round slit on a first side of the trapezoidal projection,and a second half-round slit on a second side of the trapezoidalprojection.
 10. The device of claim 2, wherein the elongate plate has atrapezoidal projection in a middle portion of the elongate plate, afirst half-round slit on a first side of the trapezoidal projection, anda second half-round slit on a second side of the trapezoidal projection.